Keep iPhone Screen On (when plugged in)@cawas Because the Auto Lock setting doesn't differentiate between battery and external power. In other words, I have to remember to switch Auto Lock back to my preferred on-battery setting of 1 min or risk stuffing my phone in my pocket after forgetting to lock it, and then having a dead battery in a couple hours (or worse, losing my phone and having it lying on the street unlocked). iTunes, on the other hand, will only keep the phone unlocked on battery power. If you're good about remembering to manually lock your phone, then Auto Lock might work for you.